Dialysis treatment is performed by extracorporeally circulating blood of a patient in a blood circuit and by removing blood waste materials in the blood through a dialyzer connected to the blood circuit. A dialysate prepared to have desired concentration by diluting an undiluted dialysate with a diluent is supplied to the dialyzer. For example, a dialysis system called a central system type includes not only a monitoring device for performing dialysis treatment on the patient by using the dialyzer, but also a water treatment device which can produce clean water (diluting water or washing water), a dissolving device which can produce the undiluted dialysate, and a dialysate supplying device which can produce the dialysate and supply the dialysate to the monitoring device.
Then, the individual devices involved in the dialysis system include pipes for circulating the dialysate, the undiluted dialysate and the clean water. In general, during a predetermined period of time when treatment is not performed, a disinfecting process is performed in order to disinfect the pipes. For example, as a technology which can disinfect the pipes of a dialysate supplying device, there is provided a mixing apparatus in which a flow route (hereinafter, referred to as a “main unit”) for circulating water (hereinafter, referred to as a “main liquid”) from a water supply source is connected to a tip of a flow route (hereinafter, referred to as an “auxiliary flow route”) which can circulate a disinfecting solution (hereinafter, referred to as an “auxiliary liquid”), and in which an electromagnetic valve (hereinafter, referred to as a “switching device”) and a pump (hereinafter, referred to as a “pressurizing device”) are provided near a merging portion of the main unit in the auxiliary flow route (refer to PTL 1).
Then, whereas when the disinfecting is not performed (treatment is performed), the switching device is turned off and the pressurizing device is stopped, when the disinfecting is performed on the pipes, the switching device is turned on and the pressurizing device is operated. In this manner, the disinfecting process is performed by injecting the auxiliary liquid to the main unit, mixing the auxiliary liquid with the main liquid, producing the disinfecting solution having the predetermined concentration, and circulating the disinfecting solution in the pipes. Then, if the switching device is turned off, it is possible to prevent the auxiliary liquid from reaching the main unit when the disinfecting is not performed. One example of a device may be found in Japanese Unexamined Patent Application Publication No. 63-38466, the teachings of which are incorporated by reference herein for all purposes.